Josh,
The links to the blogs are great which explain the definition, calculation method, and reasoning for their use, however, they are general in nature.
Wendy did not provide figures in order to properly calculate this particular investment and I am quite worried about her even thinking of investing in such a large building if she has no idea about cap rates. That could be a financially fatal mistake.
In addition, the 50% rule that I keep seeing on this forum is for a quick scan evaluation of properties and not to be used to calculate true cap rates, dscr, operating expenses, NOI, ROI, or any other pertinent figures, particularly with a complex this size.
Wendy, my advice is to get some professional help evaluating this investment such as a very experienced investor, CPA, and/or RE attorney. There are many determining factors you need to calculate in order to arrive at the asking price's true cap rate and what cap rate it is currently worth.
Wendy, send the exact figures to me including taxes, insurance, management, utilities, administration/professioanl fees, makeready expense, trash, landscaping, and all other operating expenses and I will calculate the value for you as well as the asking cap rate, dscr, and price at which I would offer.
Hope this was helpful